Mast or support for life-saving apparatus



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l|' I I n I Patented Jan. 18, 1927.

UNITED STATES PATENT OFFICE.

FRITZ MAYER, OF ULM-ON-THE-DANUBE, WURTTEMBERG, GERMANY, ASSIGNOR TO THE FIRM OF G. D. MAGIRUS A.-G., OF ULM-ON-THE-DANUBE, WURTTEMBERG,

GERMANY.

MAST OR SUPPORT FOR LIFE-SAVING APPARATUS.

Application filed August 1, 1921., Serial No. 488,977, and in Germany January 15, 1915. Renewed November 14, 1925.

(GRANTED UNDER THE PROVISIONS 0'! THE ACT OF MARCH 3, 1921, 41 STAT. I, 1313.)

This invention relates to life-saving and fire extinguishing apparatus and particularly to apparatus having an extensible ladder or mast which is capable of assuming various positions of inclination with respect to the plane of the ground.

The present invention involves carrying forward the invention set forth in my copending application #488,976 which matured into Letters Patent i l-1,528,448, March 3,1925.

A general object of this invention is to provide an improved salvage apparatus in which the actuation and movement of the extensible ladder is automatically controlled in a manner to confine the center of gravity of the ladder within known safety limits for all positions assumed by the laddeigwhereby maximum stabilitiy is afforded. In order to safely position the center of gravity for all positions of the ladder and to obviate all tendency of the ladder to overturn, the invention contemplates the actuation of the extensible ladder by an elevating or inclining gear and by an independently operated extending gear, the said actuating mecha nism being coupled by an automatically-acting regulating and locking mechanism, in such a manner that the extending and elevating operations are rendered dependent on each other so that as the ladder assumes its various positions of inclination it can be extended only a predetermined amount in proportion to the inclination, and converse ly, in the various stages of extension, the ladder can be inclined only so far as is compatible with the center of gravity being maintained within a safety zone.

A further object of the invention resides in the provision of compensating mechanism for initially adjusting the actuating mechanism when the apparatus is used upon an inclined supporting surface in order tomodify the normal activity thereof in accordance with the amount of departure of the supporting surface from the horizontal. The compensating mechanism permits the safe operation of the apparatus upon inclined surfaces, such, as frequently encountered in the ordinary uses of apparatus,

by assuring the proper positioning of the center of gravity within stable limits in spite of the tilted position of the apparatus carrying the ladder.

For a more complete understanding of the invention, together with further objects and advantageous details and combination of parts, reference may be had to the annexed specification and the accompanying drawings illustrating an embodiment thereof, in which:

Fig. 1 represents diagrammatically a life-saving apparatus in several positions of adjustment,

Fig. 2 shows diagrammatically the controlling device in a position of rest,

Fig. 3 shows diagrammatically the controlling device when the ladder is elevated but unextended,

Fig. 4 shows diagrammatically the controlling device when the ladder is completely elevated and extended,

Fig. 5 is a side elevation of the apparatus constructed in accordance with this invention,

Figs. 6, 7 and 8 show the assembly of the operating mechanism and the control and locking device in the same position as in Figures 2, 3 and 4,

Figs. 9 and 10 illustrate the apparatus in use upon an inclined supporting surface, the letter S indicating the center of gravity of the ladder,

Fig. 11 is a front elevation of the controlling and compensating mechanism,

Fig. 12 is a side elevation of the mechanism shown in Fig. 11,

Fig. 13 is a plan view thereof,

Fig 14 is a front view of the complete actuating mechanism, and

Fig. 15 is'a view in side elevation showing one method of operating the ladder sections from the elevating drum.

The general features of the type of lifesaving apparatus herein shown are described in detail in my Patent #1,528,448 hereinbefore referred to and only such portions of the illustrative apparatus, therefor, as are intimately related with the novel features of this invention will be described herein in 109 detail, and for further information as to details of construction of the apparatus, reference may be had to the prior patent.

In a general aspect, the apparatus comprises a rotatable supporting frame 1 on which is mounted a fluid pressure or hydraulic actuating mechanism 2. Projecting from the actuating mechanism are driving shafts 8 and 4t, the former'acting through mechanism hereinafter described to elevate a ladder or mast, while the latter shaft serves to extend or telescope the ladder. Power is transmitted from the driving shaft 8 to an erection spindle 11 by cooperating toothed wheels 7 and 8 and a set of bevel wheels 9 and 10. The spindle 11 is externally threadedand has mounted thereon an internallythreaded nut 12 affixed to-the lower end of a tube 13, the latter lJQlDg'PlVOiGLl at its upper end, as at 14:, to the lower end of the ladder frame 6. From this construction, it w.-ll be apparent, that the ladder frame 6 may be rotated about its horizontal supporting pivot 5 in either direction by the rotation of the shaft 3. The shaft 4 is connected by chains or belts 16 and 17 to an elevating drum l8, movement of which is utilized to effect the extension or telescoping of the ladder. Neither the form of the extensible ladder employed nor the connection between said ladder and the elevating drum 1.8 constitute an essential part of the present invention and therefore will be described generally. Theladder illustrated in Fig. 15 comprises a plurality of sections 6 6 6 and 6 adapted to move telescopically with respect to one another. A wire rope or cable 6,

secured to the extend ng drum. 18 is wound on and off the drum when the latter is rotated in a clockwise or counter-clockwise direction respectively. The free end of the cable 6 passes over a pull 6 mounted near the top of the ladd r section 6, and is secured at the bottom of a second ladder section 6 When the cable is wound up on the drum, the second ladder section which is slidably mounted on the first ladder section will be extended. The end of a second cable 6 is secured to .the top of the ladder section 6 and passes over a pull 6 mounted near the top of the second ladder sect'on 6 and is secured to the bottom of the third ladder section. 6. The extension ofv the second ladder section will, by means of this cable, extend the third ladder section. The end of a third cable (i is secured to the upper end of the ladder section 6 passes over a pull 6 near the top of the third ladder section 6 and is secured to the bottom of the fourth ladder section 6. An upward movement of the ladder section 6 will also move the ladder section 6 up. Thus the wfnding of the cable 6 on the drum 18 will extend all of the ladder sections. When the cable 6 is unwound from the drum by the rotation of the latter in a clockwise direction, the ladder sections will move in a downward direction in a manner readily understood. Rotation of the driving shafts 3 and l is effected by fluid operated gears within the mechanism 2, the said gears being in turn connected to a convenient source of power. Control cocks 72. and 2' are provided through which the fluid or liquid intended to operate the mechanism is conducted as desired to the various gears within the mechanism 2 where the power is to be applied. The cocks are operated by levers 22, scales :23 being provided to indicate the movement and position of the cooks.

While the extension and elevation of the ladder may be controlled through the cocks h and z, provision must be made for preventing the operator from extending the ladder beyond a safe point until the ladder has been previously placed at the proper angle to retain stability of the apparatus or, conversely, from lowering the ladder until. the same has been telescoped the proper amount. In other words, there is a safety zone for the center of gravity of the ladder which must be observed in order to eliminate danger from tilting and over-turning. lVhen the ladder is being extended, the center of gravity is displaced progressively laterally away from the base of the ladder. Should the center of gravity travel too great a distance d rectly laterally from the base of the ladder, there is imminent danger of the apparatus tipping over, as will be w ll understood by those skilled in the art. It is well-known that the proper manner to eliminate this danger is to elevate the ladder more and more in direct proportion to the amount of extension, so that while the cen ter of gravty moves further away from the base of the ladder, the lateral displacement of the center of gravity is simultaneously being reduced. Assuming that the ladder has been inclined to a given angle and has been extended the maximum amount which stability permits at that angle, a reduction in degree of inclination must be preceded by a shorten ng of the ladder in order to shift the center of gravity to a position conforming to the law of stability (see Fig. 1). On the other hand, if the ladder, is to be extended further, the inclination of the ladder must be increased to accomplish the same result.

In order to remove the danger of human error and to eliminate constant attention on the part of the operator, this invention contemplates the automatic control of the extending and inclining operations, so that movement of the ladder beyond the safety point is precluded. The mechanism which accomplishes this result is diagrammatically illustrated in Figures 2 to 4: inclusive. The drive shafts 3 and 4 which serve to incline and extend the ladder are provided with curvilinear discs or cams a and b, respectively. Rollers d and e are arranged above the cams a and b in position to engage the peripheral surfaces thereof. The rollers d and e are mounted upon opposite ends of a lever c, the position of which is controlled by said rollers. At the middle of the lever 0, a depending rod f is provided upon the lower end of which is mounted a cross bar 9. The outer ends of the cross bar 9 are arranged in the path of stops provided upon the cooks l2. and 2', so as to control, within limits, movement of the cooks in a manner hereinafter described more fully. The position of the parts when at rest is indicated in Fig. 2. Fig. 3 shows the position of the parts when the ladder is elevated but still unextended, while in Figured the position of-the elements is shown when the ladder is completely extended and elevated.

Figures 6, 7 and 8 illustrate a practical application of the diagrammatical views shown in- Figures 2, 3 and 4. Referring more specifically to these figures, 0 denotes a lever extending between cams a and b mounted on driving shafts 3 and 4:, respectively. A depending rod f is connected to the middle portion of the lever c and is slidably guided in the frame of the machine. At the lower end of the rod 7' is attached a cross-member g which serves, by its extremities, to limit and control the movements of the cocks h, i and also, when required, to close said valves at certain stages in the operation of the apparatus. For this purpose the cross-member is arranged in the path of crank pins m mounted eccentrically on the cocks. Movement of these pins upwards or downwards from a neutral position, produces a change in the position of the cooks which in turn results in a movement of the ladder. In the horizontal position, as shown in Figs. 2 and 6, both cocks are in the zero or neutral position to which they are brought by a special device which is not a part of this invention. Other positions of the cooks are indicated in broken lines. The line R represents the position required for the cock h when the ladder is to be elevated. For the purpose of inclining the ladder downwardly the cock must be adjusted into the position N. When in the position A, the cock 2' causes the ladder to be extended and when it is in the position E, the ladder is telescoped. WVith the completion of one cycle in the elevation of the ladder, the earn a has returned so as to bring about a displacement of the lever c, as in Figs. 3 and 7. If the ladder is to be extended under these conditions,v the cock 1' must be move into the position A. The extension of the ladder then proceeds until, after a predetermined movement, the further extension is stopped by the automatic return of the cook 71 to neutral position through the activity of cross bar g, rod f, lever 0, and cam b. The position of such parts as the end of an extension cycle is shown in Figs. 4 and 8.

In these three fundamental positions, as in the execution of all further movements, there is only one definite manipulation of the apparatus possible at any stage in the cycle of operations, and this must be observed by the operator. In the initial position, illustrated in Figs. 2 and 6, for instance, the ladder can clearly be elevated but it cannot be extended as the cross-member g occupies such a position that, on the one hand, the cock h is adjustable in the direction R and, on the other hand, the cock 7; is constrained against adjustment in the direction A. The automatic control of the cooks and the limitation of their operation is effected both during the elevation and the lowering of the ladder. Thus, when the ladder is partially elevated, the extension ceases at a definite point in consequence of the movement of the lever 0 by reason of the form of the cam b, the cross-member g being raised and cook c brought to the zeroposition. Only when further elevation has taken place and the cam a has rotated in the direction of the arrow R does the crossmember 9 descend, setting the cock 2' free for adjustment in the direction A and rendering further extension of the ladder possible. This procedure takes place in the reverse order when the ladder, in a partially elevated condition, is being lowered: thus, a further inclination of the mast is only possible when a corresponding shortening has been effected, by the cam b turning in the direction A and the cross-member g descending through the medium of the lever 0, so that the cock it can be adjusted in the direction 'N.

In order that the mutual dependence on each other of the movements of extension and inclination hereinbefore described may begin or cease at a definite position of inclination, (for instance, position II, Fig. 1), the cam a may, along a portion of its periphery, be so formed that for a partial rotation of the cam during elevation or inclination, the lever 0 remains undisturbed so that the extension of the ladder may proceed without hindrance. The complete rotation of the cam a corresponds to the extent of the incl ning and elevating movements as the ladder passes from the position I to the position II or conversely from II to I (of Fig. 1.). The form of the cam or disc, as shown in the figures, may be spiral, but the path at each portion of the periphery of the disc may be arranged around a single centre of curvature.

The essential feature of the improved construction illustrated in Figs. 9-13 consists in Ill! the provision of means for adjusting the controlling and locking mechanism in order to compensate for variations in the normal position ot the centre of gravity owing to the uneven condition of the ground upon which the apparatus rests. In order to modify the operation oi? the mechanism so that the mechanism can always be relied upon to act with safety, even on uneven or inclined surfaces, an initial adjustment of the mechanism is provided whereby the time and period of connection and disconnection of the inclining and of the extending mechanisms with the source of power is prolonged or shortened in accordance with the varying conditions of use. 'To this end, two levers 2st and 25, act on a Cl'OSS-H18Il1bGI 28 which is provided at its ends with long slots '29 for the reception of studs on the ends of-the levers 2d .and 25. \Vith this cross-member 28 is connected a rod 30 to which is secured a cross-member 31 serving for limitation of the movement of cocks 19 and 20, and also under certain conditions to close the cooks. The cross-member 31 is adapted to contact with pins or projections 32 provided eccentrically upon the cocks. In Fig. 11, the different positions of the cocks are indicated. It the cock 20 is adjusted to the position A, the ladder is extended and in the position E it is retracted. N indicates the position of the cock for inclining the ladder downwardly and R for inclining the ladder upwardly.

Connection between the cross-member 28 and the rod 30 is effected by a spindle 34, mounted in a head or boss 33 of the rod 80. The spindle 34 carries a crank pin or eccentrically disposed ph 35 which pivotally supports the C10SS111111b6I 28. In the example of construct-ion described, the eccentrically placed pin is carried by an arm 36 mounted on the spindle 3d. The spindle 34 is also fitted at its opposite end with a hand lever 37, adapted to move laterally to a determined degree in the directions incicated by the arrows in Fig. 11, and which is held in various positions of adjustment by means of a rack-segment 38, provided upon the head 33 oi the rod 30, and a pin 39 on a laminated spring fitted to the lever 37. A water or spirit level 40 is fitted to the hand lever 37, to indicate the degree to which the lever must be perated. lVhen the apparatus is used on a surface inclined from the horizontal, the hand-lever is moved laterally until the air-bubbleof the water or spirit level, which had naturally been displaced, has once more returned to its midposition. The hand-lever then occupies the position indicated in Figs. 9 and 1 0 by the full lines. These two figures also indicate by dotted lines the position of the water level before adjustment of the hand lever, the water .level'being shown slightly above its correct position for clearness of illustration. From the construction described, it will be apparent that movement of the handlevers 37 to the left or right as viewed in Fig. 11 will result in an upward or downward shifting of the cross-member 31. Thus, in conditions as shown in Fig. 9 the cross-member occupies a lower position than normally. As a result the cross-member, on moving upwards, by reason of the action 01 the lever 25 travels a greater distance, and the automatic return of the cook 20 into its mean position is delayed. The disengagement of the extension mechanisn'i is therefore corr-espon-clingly delayed, in accordance with the more favorable position of the centre of gravity of the ladder in these conditions.

When the apparatus is situated as in Fig. 10, the cross-member 31 is adjusted to a higher level by the movement of the handlever 37, so that the distance for the upward movement is shortened and an earlier disengagement of the extension mechanism follows. The upward and downward movements of the apparatus is, like the movement of extension, permitted within correspondingly altered limits, in such a manner that, as shown in Fig. 9 the inclination may be increased, whereas in Fi 10, that is, in more favorable conditions, only slight movement of inclination is permitted. The controlling and locking mechanisms are thus rendered capable of governing the movements of the mast or ladder even upon an uneven or sloping ground surface, so that in no case is it possible to exceed the limits of permissible movement as determined by the eii'ect of the force of gravitation.

Since the manner in which the different parts of the apparatus operate to perform their functions and the sequence of operation as a whole have been set forth in connection with the detailed description, no further description of the operations is necessary tor a complete understanding of the invention.

Havin thus particularly described the nature of my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A device or" the class described having, in combination, an extensible ladder, a support for said ladder, a horizontal pivot for mounting said ladder upon the support, means for rotating the ladder about said pivot into inclined positions with respect to the horizontal, means for extending said ladder, and means for preventing the actuation of the extending means until the ladder has been rotated into a predetermined inclining position.

' 2. A device of the class described having, in combination, an extensible ladder, a support for said ladder, a horizontal pivot for mounting said ladder on said support, means for rotating said ladder about said pivot into positions inclined with respect to the horizontal, means for extending said ladder, means for controlling the actuation of said rotating and extending means, and means interposed between the rotating and extending means and the controlling means for preventing the actuation of the extending means until the ladder has been moved into a predetermined inclined position.

3. A device of the class described having, in combination, an extensible ladder, a support, a horizontal pivot for mounting said ladder on said support, hydraulically actuating means for moving the ladder about said pivot into various positions of inclination with respect to the horizontal, hydraulically actuating means for extending said ladder, means for controlling the operation of each of said hydraulically actuating means, and locking means for limiting or preventing the actuation of the controlling means in accordance with the limit of stability of the ladder as determined by the angle of inclination and the amount of extension of the ladder.

a. A device of the class described having, in combination, an extensible ladder, a support, a horizontal pivot for maintaining said ladder on said support, a driving shaft for moving the ladder about said pivot into various positions of inclination with respect to the horizontal, a driving shaft for extending the ladder, a source of power, means for connecting said driving shafts to the source of power to incline and extend the ladder, and locking means adapted to prevent connection between the shaft for extending the ladder and the source of power unless the ladder has been previously inclined to a predetermined degree.

5. A device of the class described having, in combination, an extensible ladder, a support, a horizontal pivot for mounting said ladder upon said support, a source of power, a driving shaft for moving the ladder about said pivot into various positions of inclination with respect to the horizontal, means for connecting said drive shaft with the source of power, a second drive shaft for extending said ladder, means for connects ing the second drive shaft to said source of power, and means controlled by said drive shafts for preventing the connection of either of said shafts to the source of power unless the center of gravity of the ladder is within a predetermined locality.

6. A device of the class described having, in combination, an extensible ladder, a support, a horizontal pivot for mounting said ladder upon said support, a source of power, a drive shaft for moving the ladder about said pivot into various positions of inclination with respect to the horizontal, a second drive shaft adapted to extend and telescope said ladder, means for connecting said second drive shaft to the source of power, and means controlled by the inclination andextension of the ladder for regulating the activity of each of said connecting means so as to prevent the movement of the ladder to a position in which the center of gravity thereof will fall outside of a predetermined area.

7. A device of the class described having, in combination, an extensible ladder, a support, a horizontal pivot for mounting said ladder upon said support, means for inclining said ladder about said pivot, into various angular positions, means for extending and telescoping said ladder, a source of power, a control device adapted to move in one direction from a neutral position to connect the source of power with the inclining means and cause the ladder to move toward a vertical position and when moved in the opposite direction from the neutral position to cause the ladder to move toward a horizontal position, a second control device adapted when moved in one direction from a neutral position to connect the source of power with the extending and telescoping means to cause the extension of the ladder and when moved in the opposite direction from a neutral position to cause the ladder to be telescoped, and meansbetween the inclining and extending means and the controlling devices for preventing the move ment of the latter unless the amount of extension and degree of inclination of the ladder bear a predetermined relationship.

8. A salvage apparatus having an extensible ladder, a support, a horizontal pivot. for mounting the ladder upon the support, mechanism for moving said ladder about said pivot into various positions of inclination with respect to the horizontal, the said mechanism including a driven shaft, mechanism for extending and telescoping said ladder, the said extending mechanism including a driven shaft, a source of power, and controlling devices for connecting and disconnecting the said driven shafts with the source of power, in combination with a cam fixed upon each of said driven shafts, a movable locking member adapted to engage said controlling devices to lock the ladder and prevent the inclining or extension of the ladder, and connections between the locking member and the cams to move the locking member into and out of locking position in accordance with the position of said cams.

9. A salvage apparatus having an extensible ladder, a support, a horizontal pivot for mounting the ladder upon the support, mechanism for moving said ladder about said pivot into various positions of inclination with respect to the horizontal, the said mechanism, including a driven shaft, mecha nism for extending and telescoping said ladder, the said extending mechanism including a second driven shaft, a source of power, and controlling devices for connecting and disconnecting the said driven shafts with the source of. power, in combination with' a cam fixed upon each of said driven shafts, projections upon each of said controlling de vices, a movable member located in the path of said projections adapted when in one position to engage the said projections and lock the controlling devices against movement, and. connections between said cams and the movable member for shifting the latter into or out of locking position to prevent or pernit the operation of the controlling members.

10. A salvage apparatus having an extensible ladder, a support, a horizontal pivot for mounting the ladder upon the support, mechanism for moving said ladder about said pivot. into various positions of inclination with respect to the horizontal, the said mechanism including a driven shaft, mechanism for extending and telescoping said ladder, the said extending mechanism including a second driven shaft, a source of power, and controlling devices for connecting and disconnecting the said driven shafts with the source of power, in combination with a cam fixed upon each of said driven shafts, projections upon each. of said controlling de vices, a movable member located in the path of said projections adapted when in one position to engage the said projections and lock the controlling devices against movement, and connections between said cams and the movable member for shifting the latter into or out of locking position to prevent or permit the operation of the controlling membore, the said connections comprising a cross bar, a roller mounted upon each end of said bar in position to engage one of said cams, and a rod depending from said. cross bar and rigidly connected to said movable member.

11. A salvage apparatus having an extensible ladder, a support, a horizontal pivot for mounting, the ladder upon the support, mechanism for moving said ladder about said pivot into various positions of inclination with respect to the horizontal, the said mechanism including a driven shaft, mechanism for extending and telescoping said ladder, the said extending mechanism including a second driven shaft, a source of power, and controlling devices for connecting and disconnecting the said driven shafts with the source of power, in combination with a cam fixed upon each of said driven shafts, projections upon each of said controlling devices, a movable member normally located in the path of said projections to lock the controlling device against movement to a position for inclining or extending said ladder, the said movable member being shiftable away from said projections to release the controlling device, and connections between said cams and the movable member for shifting the latter into looking or unlocking position to prevent or permit the operation of the controlling members, the said movable member in its movement from unlocking to locking position serving to move the controlling devices into position to stop the extension or inclination of the ladder.

12'. A device of the class described; having, in combination, an extensible ladder, a sup port, a horizontal pivot for mounting said ladder upon the support, actuating means for moving the ladder about said pivot into various positions of inclination with respect to the horizontal, actuating means for extending and telescoping said ladder, means for controlling the activity of each actuating means by the other to retain the center of gravity of the ladder within predetermined localities, and a compensating means for modifying the normal action of the controlling means when the device is used upon an uneven surface.

13. A device of the class described having, in combination, an extensible ladder, a support, a horizontal pivot for mounting said ladder upon said support, actuating means for moving said ladder about said pivot into various positions of inclination with respect to the horizontal, actuating means for extending and telescoping said ladder, a movable locking device for said actuating means adapted when in one position to prevent actuation of said actuating means to cause downward inclination or extension of the ladder, means between the locking device and said actuating means for moving the former into locking position when the ladder has reached the limit of stability, and compensating means connected to said locking device for moving said, device into a position of initial adjustment when the apparatus is used upon an uneven surface.

14. A device of the class described having, in combination, an extensible ladder, a support, a horizontal pivot for mounting said ladder upon said support, means for moving said ladder about said pivot into various positions of inclination with respect to the horizontal, means for extending and telescoping said ladder, a control device adapted when moved in one direction to cause the ladder to move toward a horizontal plane, and when moved in an opposite direction from neutral position to cause a movement of the ladder toward a vertical plane, a second control device adapted when moved in one direction from a neutral position to actuate the extending means to extend the ladder and when moved in the opposite direction from a neutral position to lllO cause a telescoping of the ladder, a movable locking device adapted when in one position to permit one of the controlling devices to be moved in a direction to cause the ladder to move toward a horizontal plane and to prevent the other controlling device fro: movement in a direction to cause the extension of the ladder, connections between a portion of said actuating means and said locking device for moving said locking device into and out of locking position, and compensating means connected to said locking device to move said device into a posi tion of initial adjustment when the apparatus is used upon an uneven surface.

15. A salvage apparatus having an extensible ladder, a rotatable support, a horizontal pivot for mounting the ladder upon said support, mechanism for moving said ladder about said pivot into various posilions of inclination with respect to the horizontal, said mechanism including a driven shaft, mechanism for extending and telescoping said ladder, said extending mechanism including a driven shaft, a source of power, and controlling devices for connecting and disconnecting said driven shafts with the source of power, in combination with a cam fixed upon each of said driven shafts, a movable member adapted to engage said controlling devices and arrest the extension and inclining operations, connections between said cams and said movable member for controlling the movement of said member in a predetermined manner, the said connections comprising a double lever, a cam roller upon the outer ends of said lever adapted to engage the cams on said driven shafts, a rod extending between said double lever and the movable locking member and compensating mechanism for initially adjusting the position of said movable member when the apparatus is used upon an uneven surface, said compensating mechanism including an adjustable connection between said rod and said lever.

16. A salvage apparatus having an extensible ladder, a rotatable support, a horizontal pivot for mounting the ladder upon said support, mechanism for moving said ladder about said pivot into various positions of inclination with respect to the horizontal, said mechanism including a driven shaft, mechanism for extending and telescoping said ladder, said extending mechanism including a driven shaft, a source of power, and controlling devices for connecting and disconnecting said driven shafts with the source of power, in combination with a cam fixed upon each of said driven shafts, a movable member adapted to engage said controlling devices and arrest the extension and inclining operations, connections, between said cams and said movable member for controlling the movement of said member in a predetermined manner, the said connections comprising a double lever, a cam roller upon the outer ends of said lever adapted to engage the cams on said driven shafts, a rod extending between said double lever and the movable locking member, and compensating mechanism for initially adjusting the position of said movable member when this apparatus is used upon an uneven surface, said compensating mechanism comprising a bearing mounted upon the upper end of said rod, a shaft mounted in said bearing, a link connection between one end of said shaft and said double lever, a handle upon the other end of said shaft for rotating said shaft to cause a shifting of said rod with respect to said lever, means for holding said handle in adjusted position, and a level ing device for indicating the position of said handle.

In testimony whereof I aflix my signature.

FRITZ MAYER. 

